Electromagnet-coil.



BEST AVAILABLE COP F. W. EEVES. ELEGTROMAGNET COIL.

APPLICATION FILED 13110.28, 1909.

1,000,440, Patented Aug. 15, 1911.

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FREDERICK W. REEVES, OF PITTSBURG, PENNSYLVANIA ELECTROMAGNET-COIL,

BEST AVAILABLE COP! To all whom it may concern:

Be it known that I, FREDERICK 1V. REEVES, a: citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain-newand useful Improvements in Electromagnet-Coils; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accom anying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification. y

'My invention relates to improvements in coil winding for various purpo" 'ing especially adapted for field magi 0 an erators and motors, transformers, 1dr iron coils, etc., and has forits objects to reduce the-heating and increase the' eflkiency or magnetic efl'ectwith less-loss of current.

-I=.'attain my. objects by 'means df'eertain improvements in the windin 'of the coil, as willbe: hereinafter-amen; fully set forth in the accompanying specification and pointed out in the appended claims.

In the accompanying drawings forming a part of this specification,'Figure 1, is a erspective view of a simple form of magnet illustrating the complete application of the windin to a magnet core. Fig. 2, is a plan ;view 0 the preferred winding as it would appear were it straightened out. F i .3, is a similar view of a modified form 0% the winding;

Theprinciples involved in my improved winding will be best understood b comparative' statements of well known acts in connection with the description of the invention. If .i'tdo'e assumed,- that a fluid conducting pipe be coiled and has several successive steps or connectedsections, each onehalfitlieibross-sectional area and double the coiled length of the preceding section, then the first'section' being twice the diametric area of the second section, and the second sect-ion twice as iararound its'coiled length as that of the first section, it will be readily apparent that if the fluid be supposed to flow through the pipe that it will exactly keep pace in the second section with that flowin in the first section.

"A-p yin the progressive step principle to the win ing of a magnet coil, by having Specification of Letters Patent. Patented Aug. 15, 1911. Application filed December 28, 1909. Serial No. 535,297,

that end of the conductor wire of the greatest cross-sectional area, and consequently less resistance, wound adjacent the magnet core, a higher amperage and more uniform flow of current throughout the coil is attaincd, thereby reducing the copper losses and applying the increased force to the magnet core. By this progressive step system of winding coils it can be readily understood that the current in each step is practically flowing in the samenumber of revolutions and in unison with one another throughout, it being borne in mind that the finer wire, at the outer partof-the coil, will be necessary to maintain a uniform magnetic saturation throughout, said finer-Wire beinga greater distance from the magnetic core it would require it to'beqa greater resistance to produce the same inductive action as the inner If the steps of the winding be made so that all the steps but the last one, forming the outer turns of the coil, be composed of plural strands progressively increased in each step toward the magnet core,'eve'nbet- 30 ter results are attained, as, for instance, if the coil include five steps, with the first step nearest the magnet core composed of five parallel strands, the ncxt step of four parallel strands, the/next step of three parallel 35 strands'andthe next one, adjacent the laststep of a'single strand, formed of two parallel strands, then the current in the step nearest the'magnet core will have fivepaths of equal resistance and like current efi'ect upon the --magnet core, the next step of four stra'nds will have four paths of equal resistance and like. current effect, and so on, the resistance of the 'ste strands increasin with the decrease'in t 1e number of stran s and distance of the step from the magnet core upon which it be wound. In F i'g. 2, I have shown a conductor embodying the progressive series plural strand .step principle, in which instance a series of five steps are shown,'as-an illustration, step 1 thereof beginning at the end 7 and inclu'ding five parallel strands, step 2 including four parallel strands, step'3'including three parallel strands, 'ste two arallel strands and step 5 of a sing e stran terminating at the end 8. In Fig; 1, Ivhave shown a magnet core 6 having the progressive series plural-strand step conductor, coiled thereon as it would 11f windings. 75

' which winding in itself would PY BEST AVAlLABLE CO 7 appear in practice, it bein understood that the said core' 6 may be 0 any form other than that shown.

At Fi 3 a variation in the form of winding con uctor is shown, wherein the series step by step principle is employed without the multiple strands in which winding the first step is designated as 1, followed in order by step 2, step 3', step 4: and step 5', the first step being used for the inner layers,

reatly increase the efficiency of the coil over that of the ordinary form of the coil conductor of the same cross-sectional area throughout.

It will be evident that the winding forth, ma be modified to accomplish the same resu ts, without departing from the principles involved. Having thus full shown and described my invention what claim is:

1. A coil tormed of a; conductor having greater current carrying capacity at the inner than the outer turns, said coil winding being in the same direction throughout its entirety.

2. A coil having the turns formed into a series of steps, each individual step having a different resistance, said coil, winding being in the same direction throughout its entirety.

3. A coil having the turns formed into a series of steps, each individual step having a difi'erent resistance, the step oflt'ering" theleast resistance being the innermost turns,

said ooil winding'being in the same direction throu hout its entirety.

4. coil havin the turns formed into a series of steps, each individual step having a different resistance 'and progressively" arranged, the step ofi'ering the least resistance bring the innermost turns, said coil winding being in the same direction throughout its entirety. I

5. A coil having the turns formed into a series of steps, each individual ste having a different resistance, the steps of esser resistance being each formed of a plurality of parallel strands.

6. A coil having the turns formed into a series of steps, each individual step having a different resistance, the steps of lesser resistance being each formed of a plurality of parallel strands, the step of least resistance being the innermost turns.

7. A coil having the turns formed into a series of steps, each individual step having a different resistance and progressively arranged, the one of least resistance being the innermost turns, the steps offering the lesser resistance being each formed of a plurality of parallel strands.

8. A coil having the turns formed into a as set i 9. A coil having the turns formed into a series of steps, each individual step having a dill'erent resistance, the steps of lesser resistances being respectively formed of a plurality of parallel strands of like length and resistance.

10.'A coil having the turns formed into a series of steps, each individual step having a different resistance, the steps of lesser reslstapces being each formed of a plurality of parallel strands, the strands in any one step being of like length and resistance, the step of least resistance being the innermost turns. 11. A coil havin the turns formedinto a series of steps, eaci individual step having a different resistance and progressively arranged with the one of least resistance as the innermost turns, the steps ofleast resistances being each formed of a plurality of parallel stfands, the strands in any one stop being respectively of like length and resistance.

12. A coil having the turns formed into a series of steps, each individual step having a different resistance, the steps of least resistances being each formed of a plurality of parallel strands, the step of least resistance being the innermost turns and the step of greatest resistance being a single strand and forming the outer turns, the strands in any one ofsaid steps being respectively of like length and resistance.

13: A coil having a series of steps of different resistances, the respective resistance steps being relatively arranged to produce the same magnetic induction throughout, said coil Winding being in the same direction throughout its entirety.

so i

14. A coil having a series or steps of different resistances increasing in proportion to the distance from the core upon which it is wound to cause the same magnetic induc tioni throughout, said coil winding being in the'same direction throughout its entirety.

15. An electro-magnet winding having varying resistances at different points, the part. having the smaller resistance having the greater number of turns, substantially as described. In testimony whereof, I afiix my signature, in presence of two witnesses.

FREDERICK W. REEVES.

Witnesses D. B. OAKS, R. S. HAnmsoN. 

